Mohsen Khakzad Carleton University ATLAS Experiment and the Canadian Contribution The Large Hadron Collider (LHC) at CERN will provide 14 TeV centre-of-mass proton-proton collisions. The ATLAS detector, is designed to take full advantage of the LHC discovery potential. The ATLAS detector and its experimental program will be briefly discussed, with emphasis on its Canadian content. Canada's contribution to the detector is focused on the Liquid Argon Calorimeter, particularly Endcap Hadronic Calorimeter, Forward Hadronic Calorimeter, Front End-Board Electronics, and Endcap Signal Cyogenic Feedthroughs.